The subject matter of the present invention relates to a method and apparatus for generating and displaying a virtual core analogous to a sample of a portion of the Earth formation which might be retrieved from a formation during the drilling of a wellbore (called a core), for generating and displaying a virtual plug analogous to a sample (called a plug) obtained from the core that might be retrieved from the formation during the drilling of the wellbore, and for saving/archiving one or more interactions which may be performed in connection with the virtual core.
A core is a cylindrical piece of rock that is acquired during the drilling of the wellbore. This core will be referenced as the solid core to distinguish it from the virtual core. Several measurements are made on the core which address the evaluation of the formation, and information from those measurements are incorporated into the studies of various discipline groups. Oil companies also acquire measurements, known as well logging measurements, in the wellbore of the rock formations surrounding the wellbore. If these same measurements (such as well logging measurements) could be used to describe the rock and present the rock in the form of a virtual core, data from the previous measurements (such as well logging measurements) could be translated into a form analogous to measurements performed on a solid core. Recall that the client or customer might already obtain measurements on a solid core. Therefore, if the customer has a virtual core, that customer could immediately compare any received virtual core information (which has been given to him by the subject company and represents well logging measurements) with his own measurements on the solid core and then utilize the results of that comparison to validate/calibrate the characterization of the reservoir or Earth formation located adjacent to the solid core. Therefore, the virtual core is a way of characterizing the reservoir in terms with which the customer is already familiar. The solid core permits characterization of the formation on the scale of a few centimeters. To be comparable, use of the log information is needed to describe the formation as a virtual core to similar resolution. Today, some measurements can be made on the formation at the borehole wall and placed in the form of an image that provides a spatial resolution in the order of centimeters. Other measurements can be made on the formation and recorded in the form of a log. These, typically, provide an average value at each depth in the borehole and have a spatial resolution from a few centimeters to several feet. If all such measurements can be combined, it may be possible to describe the rock on a scale similar to those on the solid core. However, such a description will be in a continuous, digital form. By using the virtual core, all aspects of the rock are available in response to the touch of a button.
In addition, some present day systems make measurements on an earth formation utilizing a well-logging tool to generate a well-log and then determine certain rock parameters from the obtained well-log, such as porosity, permeability, oil space, saturation. The log, which is a measurement of the earth formation extending outwardly from the borehole wall, can be used to create a virtual core, which is a description of the Earth formation disposed at the surface of the borehole wall. In addition, the customer extracts a piece, called a plug, from the formation rock in the solid core and he makes the same measurements on the plug, which is, typically, about one-inch diameter by one-inch long. Petrophysical properties (such as porosity, for example) measured from the plug are routinely compared to that measured from the log. Without cutting the entire one and one half feet of rock into several plugs and then averaging the measurements, incomplete and sometimes inaccurate comparisons are made. Having the aforementioned digital continuous description of a virtual core, if software could be utilized to select a corresponding point on the virtual core, then average the properties over an inch, both cylindrically and longitudinally, around the selected point, in effect, an estimate is made of the petrophysical property over similar volumes. If it is known in which direction a solid plug is taken, or the depth at which the solid plug is sampled, and if a virtual plug of the virtual core is made at the same depth and the same direction, an accurate comparison can be made.
With the solid core, information can be extracted over only one short piece of the entire length of the wellbore. Therefore, assuming possession of only one short piece of a solid core, if it is confirmed that the short piece of solid core matches a corresponding short piece of the virtual core, then a higher confidence exists that all other short pieces of solid core, if obtained, along the entire length of the wellbore would also match all other corresponding short pieces of the virtual core.
Having the formation properties captured in the form of a Virtual Core in digital format enables several computations to be interactively performed by the customer to simulate different scenarios. For example, an average of certain properties over specified formation intervals may be determined. This enables computation of the volumes of several fluids that are present in a reservoir thereby enabling an improved evaluation of the reservoir""s commercial value. In addition, simulations may be made of several different completion and production scenarios. From these simulations, a preferred scenario may be selected for a specific implementation that best matches the objectives for the well. The results of any or all of the above such interactions needs to be captured and the virtual core provides for a digital means to do this. Hence, the Virtual Core remains a current archive of our knowledge of the formation properties at a well and of our use of such knowledge in the shaping of reservoir management decisions.
An aspect of the present invention includes a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine, to perform method steps for generating a compilation of formation property data as a function of depth and azimuth in a wellbore, the method steps comprising: creating, in response to an integrated formation evaluation which includes one or more physical measurements as functions of depth in a wellbore and one or more formation properties as functions of depth in a wellbore and a facies log measurement as a function of depth in the wellbore and an image as a function of depth and azimuth in the wellbore of a physical measurement, a representation of the physical measurements and formation properties as functions of depth and azimuth in the wellbore on the condition that the each of the physical measurements and each of the formation properties as a function of depth in the wellbore can be related to the physical measurement in the image; and combining the physical measurement image as a function of depth and azimuth in the wellbore with the facies log measurement as a function of depth in the wellbore thereby generating a facies image as a function of depth and azimuth in the wellbore and determining a representation of any formation property as a function of depth and azimuth in the wellbore corresponding to the facies image on the condition that the formation property cannot be related to the physical measurement image.
A further aspect of the present invention includes a method of generating a compilation of formation property data as a function of depth and azimuth in a wellbore, the method comprising: creating, in response to an integrated formation evaluation which includes one or more physical measurements as functions of depth in a wellbore and one or more formation properties as functions of depth in a wellbore and a facies log measurement as a function of depth in the wellbore and an image as a function of depth and azimuth in the wellbore of a physical measurement, a representation of the physical measurements and formation properties as functions of depth and azimuth in the wellbore on the condition that the each of the physical measurements and each of the formation properties can be related to the physical measurement in the image; and combining the physical measurement image as a function of depth and azimuth in the wellbore with the facies log measurement as a function of depth in the wellbore thereby generating a facies image as a function of depth and azimuth in the wellbore and determining a representation of any formation property as a function of depth and azimuth in the wellbore corresponding to the facies image on the condition that the formation property cannot be related to the physical measurement image.
A further aspect of the present invention involves a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine, to perform method steps for generating a compilation of formation property data as a function of depth and azimuth in a wellbore, the method steps comprising: creating, in response to an integrated formation evaluation which includes one or more formation petrophysical properties as a function of depth in a wellbore, an interpreted electro-facies log as a function of depth in the wellbore and a multi-dimensional image of a physical magnitude such as, for example, electrical resistivity or acoustic impedance as a function of depth and azimuth in a wellbore, a representation as a function of depth and azimuth in the wellbore of the formation properties on the condition that the physical measurement in the multi-dimensional image can be related to each of the said formation properties; and combining the aforesaid multi-dimensional physical magnitude image as a function of depth and azimuth in the wellbore with the facies log measurement as a function of depth in the wellbore thereby generating a facies image as a function of depth and azimuth in the wellbore and determining a representation of any formation property as a function of depth and azimuth in the wellbore corresponding to the facies image on the conditions that a) the said formation property cannot be directly related to the physical magnitude in the image measurement and b) an average value of each such formation property can be assigned to each facies type on the facies image.
A further aspect of the present invention involves a method of generating a compilation of formation property data as a function of depth and azimuth in a wellbore, the method comprising: creating, in response to an integrated formation evaluation which includes one or more formation petrophysical properties as a function of depth in a wellbore, an interpreted electro-facies log as a function of depth in the wellbore and a multidimensional image of a physical magnitude such as, for example, electrical resistivity or acoustic impedance as a function of depth and azimuth in a wellbore, a representation as a function of depth and azimuth in the wellbore of the formation properties which are functions of depth in the wellbore on the condition that the physical measurement in the multi-dimensional image can be related to the said formation properties; and combining the aforesaid multi-dimensional physical magnitude image as a function of depth and azimuth in the wellbore with the facies log measurement as a function of depth in the wellbore thereby generating a facies image as a function of depth and azimuth in the wellbore and determining a representation of any formation property as a function of depth and azimuth in the wellbore corresponding to the facies image on the conditions that a) the said formation property cannot be related to the physical magnitude in the image measurement and b) an average value of each such formation property can be assigned to each facies type on the facies image.
A further aspect of the present invention involves a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine, to perform method steps for generating a compilation of formation property data representing a 2 and xc2xd D representation of any formation property, the method steps comprising: (a) generating an integrated formation evaluation in 1D including one or more physical 1D measurements, one or more interpreted formation properties, a 1D facies log and a 2 and xc2xd D measurement of a physical magnitude such as, for example, resistivity or acoustic impedence; (b) in response to the 1D property from the integrated formation evaluation and the 2 and xc2xd D physical magnitude measurement, creating a 2 and xc2xd D representation of the formation property on the condition that the said property can be related to the 2 and xc2xd D physical magnitude (c) in response to the 1D facies log and to the 2 and xc2xd D physical magnitude image, creating a 2 and xc2xd D representation of the facies, and (d) determining average values of any formation property for each facies type encountered in the facies log and, in combination with the 2 and xc2xd D facies image generated in step (c) above, generating a 2 and xc2xd D representation of any formation property on the condition that the said formaton property cannot be related to the measured 2 and xc2xd D physical magnitude as in step (b).
A further aspect of the present invention involves a method of generating a compilation of formation property data representing a 2 and xc2xd D representation of any formation property, the method comprising: (a) generating an integrated formation evaluation in 1D including one or more physical 1D measurements, one or more interpreted formation properties, a 1D facies log and a 2 and xc2xd D measurement of a physical magnitude such as, for example, resistivity or acoustic impedence; (b) in response to the 1D property from the integrated formation evaluation and the 2 and xc2xd D physical magnitude measurement, creating a 2 and xc2xd D representation of the formation property on the condition that the said property can be related to the 2 and xc2xd D physical magnitude (c) in response to the 1D facies log and to the 2 and xc2xd D physical magnitude image, creating a 2 and xc2xd D representation of the facies, and (d) determining average values of any formation property for each facies type encountered in the facies log and, in combination with the 2 and xc2xd D facies image generated in step (c) above, generating a 2 and xc2xd D representation of any formation property on the condition that the said formaton property cannot be related to the measured 2 and xc2xd D physical magnitude as in step (b).
A further aspect of the present invention involves a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine, to perform method steps that are responsive to a compilation of formation property data representing a 2 and xc2xd D representation of any formation property for deriving an average estimate of all formation properties over a prescribed surface or volume in the vicinity of a selection made on the compilation, the method steps comprising: selecting a location on the compilation, the compilation including one or more formation properties; and estimating an average of each formation property that falls within a predetermined diameter around the location on the compilation which was selected in the selecting step.
A further aspect of the present invention involves a method responsive to a compilation of formation property data representing a 2 and xc2xd D representation of any formation property for deriving an average estimate of all formation properties over a prescribed surface or volume in the vicinity of a selection made on the compilation, the method comprising: selecting a location on the compilation, the compilation including one or more formation properties; and estimating an average of each formation property that falls within a predetermined diameter around the location on the compilation which was selected in the selecting step.
A further aspect of the present invention involves a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine, to perform method steps for deriving an average estimate of all formation properties over a prescribed surface or volume, the method steps comprising: (a) generating an integrated formation evaluation in 1D including one or more physical 1D measurements, one or more interpreted formation properties, a 1D facies log and a 2 and xc2xd D measurement of a physical magnitude such as, for example, resistivity or acoustic impedence; (b) in response to the 1D property from the integrated formation evaluation and the 2 and xc2xd D physical magnitude measurement, creating a 2 and xc2xd D representation of the formation property on the condition that the said property can be related to the 2 and xc2xd D physical magnitude (c) in response to the 1D facies log and to the 2 and xc2xd D physical magnitude image, creating a 2 and xc2xd D representation of the facies, and (d) determining average values of any formation property for each facies type encountered in the facies log and, in combination with the 2 and xc2xd D facies image generated in step (c) above, generating a 2 and xc2xd D representation of any formation property on the condition that the said formaton property cannot be related to the measured 2 and xc2xd D physical magnitude as in step (b), (e) selecting a location on the compilation, the compilation including one or more formation properties; and (f) estimating an average of each formation property that falls within a predetermined diameter around the location on the compilation which was selected in the selecting step.
A further aspect of the present invention involves a method for deriving an average estimate of all formation properties over a prescribed surface or volume, the method comprising: (a) generating an integrated formation evaluation in 1D including one or more physical 1D measurements, one or more interpreted formation properties, a 1D facies log and a 2 and xc2xd D measurement of a physical magnitude such as, for example, resistivity or acoustic impedence; (b) in response to the 1D property from the integrated formation evaluation and the 2 and xc2xd D physical magnitude measurement, creating a 2 and xc2xd D representation of the formation property on the condition that the said property can be related to the 2 and xc2xd D physical magnitude (c) in response to the 1D facies log and to the 2 and xc2xd D physical magnitude image, creating a 2 and xc2xd D representation of the facies, and (d) determining average values of any formation property for each facies type encountered in the facies log and, in combination with the 2 and xc2xd D facies image generated in step (c) above, generating a 2 and xc2xd D representation of any formation property on the condition that the said formaton property cannot be related to the measured 2 and xc2xd D physical magnitude as in step (b), (e) selecting a location on the compilation, the compilation including one or more formation properties; and (f) estimating an average of each formation property that falls within a predetermined diameter around the location on the compilation which was selected in the selecting step.
A further aspect of the present invention involves a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine, to perform method steps responsive to a compilation of formation property data as a function of depth and azimuth in a wellbore for interacting with the compilation, the method steps comprising: interacting with the compilation of formation property data as a function of depth and/or azimuth in a wellbore thereby generating at least one result; and storing the at least one result back into the compilation in response to the interacting step.
A further aspect of the present invention involves a method responsive to a compilation of formation property data as a function of depth and azimuth in a wellbore for interacting with the compilation, the method comprising: interacting with the compilation of formation property data as a function of depth and azimuth in a wellbore thereby generating at least one result; and storing the at least one result back into the compilation in response to the interacting step.
Further scope of applicability of the present invention will become apparent from the detailed description presented hereinafter. It should be understood, however, that the detailed description and the specific examples, while representing a preferred embodiment of the present invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become obvious to one skilled in the art from a reading of the following detailed description.